Stereoscopic projection dates back to the early 20th century and was first seen in cinemas during the 1950s. Polarization control of alternate left and right eye displayed images is the preferred method for 3D cinema. In a 3D cinema, a fast projector flashes the left and right eye frames at a rate imperceptible to the human visual system. In synchronization, a fast liquid crystal modulator positioned between a projection lens and a polarization preserving screen encodes different polarization states onto the two frame sets. The audience wears glasses that can select between the different polarization states providing the different left- and right-eye views used for stereoscopic 3D. The use of a single projector is both cost effective and more robust to operation when compared to the alternative two projector approach. With separate projectors, periodic re-alignment is used, with adjustment to ensure matching of left- and right-eye image brightness and color.
The use of a single, fast, direct view TV-like display with a polarization modulator would benefit from the same advantages. This fact has already been recognized and exploited in the form of the commercially available monitor Z-Screen by RealD Inc. The polarization control panel (PCP) in the monitor Z-screen is a segmented pi-cell driven in synchronization with a naturally scrolling cathode ray tube (CRT) display. See, e.g., U.S. Pat. No. 4,281,341 to Byatt. Specific drive methods are disclosed in commonly-owned U.S. Pat. No. 6,975,345 to Lipton et al.